RDMA/uverbs: Combine MIN_SZ_OR_ZERO with UVERBS_ATTR_STRUCT

After all the rework is done it is now possible to include single flags in
the type macros. Any user of UVERBS_ATTR_STRUCT needs to zero check data
past the end of the known struct to be correct, so make this mandatory,
and get rid of MIN_SZ_OR_ZERO as a user flag.

This changes UVERBS_ATTR_TYPE to refer to a struct of exact size with not
possibility of extension, convert the few users of UVERBS_ATTR_TYPE and
MIN_SZ_OR_ZERO to use UVERBS_ATTR_STRUCT.

The one user of UVERBS_ATTR_STRUCT without MIN_SZ_OR_ZERO is just
confused. There is some padding at the end of that struct, but userspace
always provides it with the padding. The construction doesn't test if the
padding is zero, so it is pointless. Just use UVERBS_ATTR_TYPE.

Finally, rename min_sz_or_zero to zero_trailing to better reflect what it
does and hopefully avoid such mis-uses in the future.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

3 files changed, 12 insertions, 15 deletions

diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
index cb6109036129..5b59c6f0feed 100644
--- a/drivers/infiniband/core/uverbs_ioctl.c
+++ b/drivers/infiniband/core/uverbs_ioctl.c
@@ -98,14 +98,14 @@ static int uverbs_process_attr(struct ib_uverbs_file *ufile,
 		 * non-zero content, making ABI compat/discovery simpler.
 		 */
 		if (uattr->len > val_spec->u.ptr.len &&
-		    val_spec->min_sz_or_zero &&
+		    val_spec->zero_trailing &&
 		    !uverbs_is_attr_cleared(uattr, val_spec->u.ptr.len))
 			return -EOPNOTSUPP;
 
 	/* fall through */
 	case UVERBS_ATTR_TYPE_PTR_OUT:
 		if (uattr->len < val_spec->u.ptr.min_len ||
-		    (!val_spec->min_sz_or_zero &&
+		    (!val_spec->zero_trailing &&
 		     uattr->len > val_spec->u.ptr.len))
 			return -EINVAL;
 
diff --git a/drivers/infiniband/core/uverbs_ioctl_merge.c b/drivers/infiniband/core/uverbs_ioctl_merge.c
index ece5c9463dbe..f81aa888ce5c 100644
--- a/drivers/infiniband/core/uverbs_ioctl_merge.c
+++ b/drivers/infiniband/core/uverbs_ioctl_merge.c
@@ -378,7 +378,7 @@ static struct uverbs_method_spec *build_method_with_attrs(const struct uverbs_me
 				 "ib_uverbs: Tried to merge attr (%d) but it's an object with new/destroy access but isn't mandatory\n",
 				 min_id) ||
 			    WARN(IS_ATTR_OBJECT(attr) &&
-				 attr->min_sz_or_zero,
+				 attr->zero_trailing,
 				 "ib_uverbs: Tried to merge attr (%d) but it's an object with min_sz flag\n",
 				 min_id)) {
 				res = -EINVAL;
diff --git a/drivers/infiniband/core/uverbs_std_types_flow_action.c b/drivers/infiniband/core/uverbs_std_types_flow_action.c
index 143dbfdfda6f..c753a34cd984 100644
--- a/drivers/infiniband/core/uverbs_std_types_flow_action.c
+++ b/drivers/infiniband/core/uverbs_std_types_flow_action.c
@@ -367,8 +367,9 @@ static int UVERBS_HANDLER(UVERBS_METHOD_FLOW_ACTION_ESP_MODIFY)(struct ib_device
 static const struct uverbs_attr_spec uverbs_flow_action_esp_keymat[] = {
 	[IB_UVERBS_FLOW_ACTION_ESP_KEYMAT_AES_GCM] = {
 		.type = UVERBS_ATTR_TYPE_PTR_IN,
-		UVERBS_ATTR_TYPE(struct ib_uverbs_flow_action_esp_keymat_aes_gcm),
-		UA_MIN_SZ_OR_ZERO
+		UVERBS_ATTR_STRUCT(
+			struct ib_uverbs_flow_action_esp_keymat_aes_gcm,
+			aes_key),
 	},
 };
 
@@ -380,8 +381,8 @@ static const struct uverbs_attr_spec uverbs_flow_action_esp_replay[] = {
 	},
 	[IB_UVERBS_FLOW_ACTION_ESP_REPLAY_BMP] = {
 		.type = UVERBS_ATTR_TYPE_PTR_IN,
-		UVERBS_ATTR_STRUCT(struct ib_uverbs_flow_action_esp_replay_bmp, size),
-		UA_MIN_SZ_OR_ZERO
+		UVERBS_ATTR_STRUCT(struct ib_uverbs_flow_action_esp_replay_bmp,
+				   size),
 	},
 };
 
@@ -394,8 +395,7 @@ DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_FLOW_ACTION_ESP_ATTRS,
 			   UVERBS_ATTR_STRUCT(struct ib_uverbs_flow_action_esp,
 					      hard_limit_pkts),
-			   UA_MANDATORY,
-			   UA_MIN_SZ_OR_ZERO),
+			   UA_MANDATORY),
 	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_FLOW_ACTION_ESP_ESN,
 			   UVERBS_ATTR_TYPE(__u32),
 			   UA_OPTIONAL),
@@ -407,8 +407,7 @@ DECLARE_UVERBS_NAMED_METHOD(
 			    UA_OPTIONAL),
 	UVERBS_ATTR_PTR_IN(
 		UVERBS_ATTR_FLOW_ACTION_ESP_ENCAP,
-		UVERBS_ATTR_STRUCT(struct ib_uverbs_flow_action_esp_encap,
-				   type),
+		UVERBS_ATTR_TYPE(struct ib_uverbs_flow_action_esp_encap),
 		UA_OPTIONAL));
 
 DECLARE_UVERBS_NAMED_METHOD(
@@ -420,8 +419,7 @@ DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_FLOW_ACTION_ESP_ATTRS,
 			   UVERBS_ATTR_STRUCT(struct ib_uverbs_flow_action_esp,
 					      hard_limit_pkts),
-			   UA_OPTIONAL,
-			   UA_MIN_SZ_OR_ZERO),
+			   UA_OPTIONAL),
 	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_FLOW_ACTION_ESP_ESN,
 			   UVERBS_ATTR_TYPE(__u32),
 			   UA_OPTIONAL),
@@ -433,8 +431,7 @@ DECLARE_UVERBS_NAMED_METHOD(
 			    UA_OPTIONAL),
 	UVERBS_ATTR_PTR_IN(
 		UVERBS_ATTR_FLOW_ACTION_ESP_ENCAP,
-		UVERBS_ATTR_STRUCT(struct ib_uverbs_flow_action_esp_encap,
-				   type),
+		UVERBS_ATTR_TYPE(struct ib_uverbs_flow_action_esp_encap),
 		UA_OPTIONAL));
 
 DECLARE_UVERBS_NAMED_METHOD_DESTROY(